钽铌湿法冶炼废水中氨氮去除方法的试验研究

摘要

In order to reduce the concentration of NH4+-N in wastewater brought about in the process of Ta/Nb hydrometallurgy,the sorting operation of various ammonia-nitrogen wastewater brought about in the process of Ta/Nb hydrometallurgy has been studied. Experiments show that the NH3 ·H2O made from the evaporation,condensation and crystallization of the wastewater with highly concentrated ammonia-nitrogen (NH4+-N> 10 000 mg/L)can be recycled in Ta/Nb metallurgy. After the blow-off of ammonia-nitrogen wastewater with medium concentration (NH4+-N 500~10 000 mg/L) ,the ammonia concentration is less than 100 mg/L. After the ion exchange treatment of ammonianitrogen wastewater with low concentration (NH4+-N<500 mg/L), the effluent NH4+-N can meet the requirements of the First Grade of Comprehensive Discharge Standard of Urban Sewage Treatment (GB 18918-2002). This combined technology can bring higher economic benefits.%为降低钽铌湿法冶炼过程所产生的废水中的氨氮,对分类处理钽铌湿法冶炼产生的各种氨氮废水进行了试验研究.结果表明,对高浓度氨氮(NH<'+><,4>-N>10000 mg/L)废水进行蒸发、冷凝、结晶,制取的氨水可返回钽铌工业使用:对中浓度氨氮(NH<'+><,4>-N 500～10000 mg/L)废水进行吹脱,吹脱后出水氨质量浓度<100 mg/L;对低浓度氨氮(NH<'+><,4>-N<500 mg/L)废水进行离子交换法处理,出水氨氮可满足<城镇污水处理厂综合排放标准>(GB 18918-2002)规定的一级排放标准.这套组合工艺能带来较高的经济效益.